She said: "There is no evidence that women's lives are put at risk by the illegality of abortion in Northern Ireland. The criminal offence of intentionally killing unborn children does not prevent healthcare professionals from treating any medical condition that may arise during pregnancy."

The letter, published by Amnesty International, was signed by 838 medical professionals from 44 countries across the world.

It stated: "The criminalisation of abortion prevents healthcare providers from delivering timely care in accordance with their patients' wishes. It impedes and disregards sound medical judgment and can undermine the professional duty of care and confidentiality that doctors bear."

The 1967 Abortion Act does not extend here, where terminations are illegal except where the mother's life or mental health is in danger. Thousands of women travel to England to have terminations every year.

Breedagh Hughes, from the Royal College of Midwives, said: "Midwives and medics work with women who have received the devastating news that their foetus will not survive. It is immensely frustrating that we are not able to give them the care they require.

"Laws in Ireland and Northern Ireland do not stop women seeking or needing abortions, instead they force them to travel to England or resort to desperate, dangerous measures."

The Northern Ireland Human Rights Commission has taken legal action to change the law to allow abortions in some circumstances, including in cases of sexual crimes.

Pro-life campaigners have vehemently opposed any changes and have criticised the court action as undemocratic. Ms Smyth said: "Abortion is not a healthcare issue or a human rights issue. Abortion is in fact no more than the intentional killing of the most defenceless and vulnerable human being, the unborn child.

"Not one international human rights body or convention recognises a right to abortion. It is time Amnesty put its power and money into saving innocent lives."

According to Amnesty, 40% of women of childbearing age live in countries where terminations are banned, highly restricted or otherwise inaccessible. Unsafe abortions account for 47,000 women and girls' deaths every year, the organisation claimed.

Grainne Teggart, manager of Amnesty's My Body My Rights campaign, said the law was an "embarrassment". She added: "The message from hundreds of health professionals is clear: women are not criminals and criminalising abortion endangers their health. Professionals need space to make decisions without the threat of prosecution.

"It's time governments treated abortion for what it is: a healthcare and human rights issue."